x402-gated transaction receipt endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a specific transaction receipt (transaction ID 235) behind an x402 paywall. The broader lowpaymentfee.com platform advertises a suite of pay-per-request APIs spanning data & analytics, AI & machine learning (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request, settled in USDC on the Base network, with no API keys, no rate limits, and no minimum commitments required.
The specific endpoint probed (/api/v1/transactions/235/receipt) returned a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this translates to $0.02 per call, consistent with the site's advertised pricing. Payment is made via the x402 "exact" scheme to the specified payTo address. The endpoint accepts POST requests and returns application/json.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what the receipt payload actually contains. The platform appears to be a demonstration or early-stage deployment of x402-based micropayment APIs rather than a mature, fully documented service.
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction 235 via micropayment
- —Demonstrating x402 protocol-based API access on Base
- —Agent-driven pay-per-call data retrieval without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-per-call API access on Base
- —Exploring micropayment-gated API patterns
Not for
- —Production workloads requiring documented request/response schemas
- —Bulk or high-volume data retrieval where per-call pricing is inefficient
- —Users who need traditional API key authentication and rate-limit guarantees
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/235/receipt
# Returns 402 with x402 challenge; attach X-PAYMENT header with signed USDC payment to access the receipt.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no documentation of request parameters or response schema, and the docs/pricing/README pages are all empty beyond a wallet-connect prompt. The specific resource (transaction 235 receipt) is opaque with no explanation of what it returns.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —All documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no content
- —The endpoint references a specific transaction ID (235); unclear if this is a demo or a real resource
- —Platform appears to be early-stage or a demonstration; reliability and longevity are uncertain
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/transactions/235/receipt